Added sample security. Though this breaks the app.

src/main/java/de/w665/sharepulse/config/CustomAuthenticationFilter.java

@@ -0,0 +1,17 @@
+package de.w665.sharepulse.config;
+
+import jakarta.servlet.FilterChain;
+import jakarta.servlet.ServletException;
+import jakarta.servlet.ServletRequest;
+import jakarta.servlet.ServletResponse;
+import org.springframework.web.filter.GenericFilterBean;
+
+import java.io.IOException;
+
+public class CustomAuthenticationFilter extends GenericFilterBean {
+    @Override
+    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
+        // Custom logic here
+        filterChain.doFilter(servletRequest, servletResponse);
+    }
+}

src/main/java/de/w665/sharepulse/config/SecurityConfig.java

@@ -0,0 +1,29 @@
+package de.w665.sharepulse.config;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.config.Customizer;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configurers.LogoutConfigurer;
+import org.springframework.security.web.SecurityFilterChain;
+
+@Configuration
+@EnableWebSecurity
+public class SecurityConfig {
+    @Bean
+    public SecurityFilterChain filterChain(HttpSecurity http) throws Exception {
+        http
+                .authorizeHttpRequests(authorize -> authorize
+                        .requestMatchers("/admin/**").authenticated()
+                        .anyRequest().permitAll()
+                )
+                .formLogin(formLogin -> formLogin
+                        .loginPage("/login")
+                        .permitAll()
+                )
+                .logout(LogoutConfigurer::permitAll)
+                .rememberMe(Customizer.withDefaults());
+        return http.build();
+    }
+}